1. Field of Endeavor
The present invention relates to the field of turbomachines, and more particularly to a support for a turbine having a horizontally split outer casing.
2. Brief Description of the Related Art
In the case of turbomachines which operate with thermal processes, such as gas turbines, thermal expansions occur on the casing when running up, which are borne by special supports of the outer casing (see, for example, DE-UI-78 14 269 or EP-A1-0 785 389 or U.S. Pat. No. 5,542,642).
A possible configuration of such a supported turbomachine or turbine is reproduced in FIG. 1. The turbine 10 which is shown in FIG. 1 has an outer casing 18 which is split into an upper section 11 and a lower section 12 along a horizontal parting plane which goes through the machine axis 17. Upper part 11 and lower part 12 are connected or screwed to each other in a sealed manner in the parting plane via a horizontal flange 13. A plurality of vertical supports 14, 15 and 16, which by the upper end act on the outer casing 18 and by the lower end are supported on a floor or foundation (not shown), are arranged in a distributed manner along the outer casing 18.
The supports 14, 15, and 16 in this case can either act completely or partially on a separate integral casting on the outer casing 18 which results in the forces and moments which act upon the casing being increased as a result of the longer lever arm. Furthermore, a separate integral casting can possibly lead to undesirable larger transporting dimensions.
In order to avoid this, the supports 14, 15, and 16 can be brought as close as possible to the neutral axis of the casing, where the threaded flange connection is located. This, however, leads to a screw of the threaded flange connection having to be omitted for space reasons at the point where the respective support is attached. This can lead to problems with the sealing tightness of the outer casing.
Two variants of such a previously known support are shown in FIGS. 2 and 3. In the case of the variant according to FIG. 2, the upper end of a support 19, which is provided with a male thread 23, is inserted through a through-hole 24 in the lower flange 13b of the horizontal flange 13 and screwed to the lower flange 13b. A lower fastening nut 21, which is screwed onto the support 19, and an upper fastening nut 20 serve for this purpose. So that the upper fastening nut 20 can be screwed onto the support 19, a corresponding opening is provided in the upper flange 13a. A threaded connection of the two flanges 13a and 13b is not possible at this point. This also applies in the case of the variant according to FIG. 3 in which the support 19 by its male thread 23 is screwed into a corresponding threaded hole 25 in the lower flange 13b and locked with a locknut 22.